Customize Theme won't load

When I first created my direitosemcurso blog and started customizing it, everything was in order.

But now, when I try to access my wp-admin/customize page, the site never loads and the black bar on the right says "loading design tool..." forever. I opened my customize theme page on my other blogs and everything works perfectly.

I don't know if there is any correlation between the two things, but this happened after a changed my main page to a static page, something I would actually like to undo right now. I can only access my main page as direitosemcurso.wordpress.com/o-curso/.